The current trend in the medical industry is to make life-saving portable medical devices, such as portable external defibrillators, more widely accessible to non-medical personnel. As the availability of portable medical devices increases, it is expected that more places will have these devices for use in emergency situations, such as in homes, police cars, worksites, and public gathering places.
There are several types of known portable external defibrillators, some of which are commonly referred to as automatic and semi-automatic defibrillators. An automatic defibrillator monitors and analyzes electrocardiogram (ECG) of the patient once the electrodes of the defibrillators are connected to a patient and, based on the ECG analysis, automatically delivers a defibrillation shock to the patient through the electrodes without user intervention. On the other hand, semi-automatic defibrillators operate such that once the ECG analysis indicates that defibrillation is recommended, an operator is prompted to manually trigger delivery of a defibrillation shock to the patient by depressing a triggering mechanism, such as a shock button. In either case, the portable external defibrillator must contain or be connected to an energy source to generate and apply a defibrillation pulse to the fibrillating patient. To ensure true portability, most portable external defibrillators are constructed with a removable battery pack, which rests within a battery well positioned in the defibrillator body. The battery pack is constructed to supply sufficient power to operate the portable external defibrillator for a period of time. The battery pack may be either rechargeable or non-rechargeable, depending on the user's preference and the environment in which the defibrillator is to be used. One such battery pack is described in U.S. Pat. No. 5,868,790 to Vincent at el., and is presently assigned to Medtronic Physio-Control Manufacturing Corporation of Redmond, Wash.
While battery packs are successful in their present application, the overall configuration of utilizing removable battery packs as the power source of portable external defibrillators poses several deficiencies. For instance, as is well known in the art, a portable external defibrillator is unusable as a medical treatment device without the battery pack or with a battery pack that is discharged. In most situations, changing or recharging the battery pack will typically occur during normal testing of the defibrillator in a non-emergency setting. In the case of recharging the battery pack, a separate charging station is required, which is sometimes prohibitively expensive. If the user does not have a charging station, the user must have the battery pack charged and conditioned by a servicing center, prior to which time the portable external defibrillator is without a power source and will not operate if needed. To remedy this situation, additional battery packs must be purchased, which increases the overall operating costs associated with operating portable external defibrillators.
Additionally, a current user may have to change the battery pack at the site of the emergency. For example, a prior user of the defibrillator may have left a discharged battery pack in the device that is not discovered until treatment is to be initiated on a patient. Alternatively, the defibrillator could be in use when the battery pack becomes discharged, requiring the current user to replace the battery pack before continuing treatment. In either case, replacing the discharged battery pack with a charged battery pack increases the total time required to deliver treatment to the patient. Furthermore, these additional battery packs must also be purchased and charged, which again, increases the overall cost of operating the portable external defibrillator.